SB 

436 

N5 
1918 



UC-NRLF 



71 35D 



Tree increases each year m 
height and spread of branches 
by adding on new growth 
twigs 



Air supplfes carbon., 
the pr,ncVpai:foodof 
the tree.Taken inon 
under surface o-P 
leaves 



Light ana heat 
necessary for 
Chemical change* 



Leaves prepare 
the food obtamec 
from airand scyl 



Heartwood (inactive) 
gives strength 



Sapwood carries sa 
from root to leaves 



The breathing pores of 
the entire tree ,-or> leaves 
twigs, branches, trunk and 
roots take m oxygen 
Flooding, poisonous gases 
or smoke may ki I la tree 



Cambium ( 
builds the cells 



inner bark carries 
prepared food from 
leaves to cambium laye 



Outer bar-K protects 
tree from injuries 



t tips or root hair taKe 



quantity Of minerals t 
solution. 



US.DEPT OF AGRICULTURE 



FOREST SERVICE 




HOW THE TREE GROWS 

The buOS 'OO* tips ana cambium layer- a re the growing parts of : the tree' 
Vyater conTa"-,ng a srnal quanTiTy of minerals in solution is absorbed by the 
Hpots carried up tn rough Trie sapwood to the leaves and there combTnedwith 
(Carbon from The airto make food Thia -food is carried bythe ian<C. barl< "* a '* 
growing parts of the tree even cown to the root-Tips 



REPORTS OF THE 

DEPARTMENT OF CONSERVATION AND DEVELOPMENT , 
STATE OF L NEW JERSEY 



A Shade Tree Guide 

by 

ALFRED GASKILL 

State Forester 



Published May, 1918 




Union Hill, N. J. 
HUDSON PRINTING COMPANY. 

1918 




The Board of Conservation and Development 



SIMON P. NORTHRUP, President, Newark 

PERCIVAL CHRYSTIE, High Bridge 

NELSON B. GASKILL, Trenton 

CHARLES LATHROP PACK, Lakewood 

STEPHEN PFEIL, Camden 

EDWARD S. SAVAGE, Rahway 

GEORGE A. STEELE, Eatontown 

HENRY CROFUT WHITE, ..North Plainfield 



ALFRED GASKILL, Princeton, State Forester and Director 

HENRY B. KUMMEL, Trenton, State Geologist 

CHARLES P. WILBER, New Brunswick, State Fireivarden 

OFFICE, STATE HOUSE ANNEX, TRENTON. 



(2) 



A/ 5" 



Contents. 



Street Trees, 5 

Shade Tree Commission, 5 

Old trees, 5 

What to plant, 5 

Trees to avoid, 7 

Location, 7 

Intervals, 7 

When to plant, 7 

How to plant, 7 

How to keep trees healthy, 9 

Lawn Trees, 10 

Planting, 10 

"Wells" and mounds, 11 

Seashore Trees, 11 

Fertilizer, 12 

Support, 12 

What to plant, 12 

Nourishment, 12 

Water, 13 

Pood, 13 

Pruning, 13 

When transplanted, 13 

For form, 13 

For vigor, 14 

Covering cuts, 14 

Time to prune, 15 

Injuries, 15 

Broken limbs, 15 

Frost cracks, sun cracks, and winter kill, 16 

Abrasions, 16 

Cavities, 16 

Gas poison, 18 

Fire, 18 

Salt, Lime, 18 

Electricity, 18 

Diseases, 20 

Wilting, 21 

Bleeding, 21 

Insects, 21 

Biters, 22 

Suckers, 22 

Borers, 22 

(3) 

912 




Illustrations. 



FIGURE PAGE 

1. How the Tree Grows Frontispiece 

2. Young Trees Planted in Anticipation of Removal of Old Trees . . 6 

3. How to Plant a Street Tree 8 

4. A Young Street Tree Failing thru Lack of Care 9 

5. A Young Street Tree Properly Planted and Well Cared For... 9 

6. Use of Trees as Anchors for Guy Wires 10 

7. Four Types of Tree Guards 11 

8. Norway Maple Showing Very Dense Crown 14 

9. Norway Maple with Superfluous Branches Removed by 

Pruning 14 

10. Right and Wrong Ways of Treating Wounds 15 

11. The Right and Wrong of Tree Doctoring 17 

12. Trees Butchered to Make Room for High Wires 19 

13. Trees with Crowns Saved and Wires Carried on Low Poles 20 



(4) 



A Shade Tree Guide 

This bulletin will be helpful to municipal authorities and to those 
who wish to maintain vigorous, attractive trees on their properties. 
Few people realize that any tree standing beside a sidewalk, or even 
on a lawn, is out of its element (the forest), and that the strains 
and dangers to which it is subject must be counteracted in every 
way possible. The advice given refers particularly to New Jersey; 
it is applicable to most of the eastern United States. 

The value of shade trees. Tho it is now well established that a 
shade tree has a value beyond that of its wood, or the cost of plant- 
ing a new one, and that neither individuals nor public service agencies 
can injure one without becoming liable for damages, it is advisable 
always to avoid such troubles. 

Street trees and lawn trees. It is needful to distinguish between 
street trees and lawn trees because only a few deciduous species, 
and no evergreens, can be maintained on narrow paved ways, 
whereas a lawn admits a variety of trees and shrubs, deciduous and 
evergreen, that is limited only by space and climatic conditions. On 
streets and lawns close to the sea the available kinds of trees are 
few, and extreme care in their selection and nurture is required. 

Street Trees 

Shade Tree Commission. It is always advisable to have street 
trees under the control of a Shade Tree Commission, such as is main- 
tained in many communities in New Jersey and in several other 
states. These organizations can secure better results than indi- 
viduals. 

Old trees. An established tree, even of poor kind, is better than 
a newly planted one. Unless an old tree is decrepit or a nuisance it 
should be saved until a new one can be started to take its place. If 
young trees are planted between old ones before the latter have to 
be removed there will be less objection to taking away the unde- 
sirable ones than there may be if gaps are created. (Fig. 2.) 

What to plant. In the choice of trees for street planting there is 
no room for experiments ; one must select a kind that will live, and 
give satisfaction, for many years under fixed, and usually unfavor- 
able, conditions. It is generally agreed that an acceptable street tree 
must be of form suited to the space, hardy and not subject to insects 
or disease, fairly rapid in growth, a good shade producer, and neat in 
that it drops no objectionable litter. The list of available trees is 
practically limited to the following. In most cases choice should be 
restricted to the kinds indicated by italic type. 

(5) 



SHADE TREE GUIDE. 




Fig. 2. Young Trees Planted on an Inside Line in Anticipation of 
the Removal of Decadent Old Trees on the Curbing. 



The Best Trees for City Streets 


Narrow Streets. 


Average Streets. 


Wide Streets. 


(less than 60 feet 
wide between building 


(60 to 90 feet wide 
between building 


(over 90 feet wide be 


lines.) 


lines.) 


tween building lines. 


Gink go 


Scarlet Oak 


White Elm 


Norway Maple 


Ginkgo 


Red Oak 


Hackberry 


Norway Maple 


Sycamore 


Green Ash 


Red Oak 


Tulip Poplar 


Red Gum 


Sycamore 


Sugar Maple 


Red Maple 


Hackberry 


White Oak 


Honey Locust 


Red Maple 


Basswood 




Pin Oak 


Red Gum 




Basswood 


Scarlet Oak 




White Ash 


Ailanthus 




Red Gum 






Sugar Maple 






Honey Locust 






Horse Chestnut 





STREET TREES. 7 

The tree to be planted will be more likely to thrive if it comes 
from a reputable nursery than if it grew wild, because nursery cul- 
ture induces the development of compact root systems and lessens 
the risk of moving. The larger the mass of small feeding roots 
that is taken up, and the more earth that is moved with them, the 
quicker and better will the tree establish itself. Red Gum has 
very tender roots and is rarely planted successfully unless it is 
moved with a "ball" the same as an evergreen (p. 10). A tree 
of any kind should be healthy, symmetrical, and, as a rule, have a 
breast-high diameter of between 2 and 3 inches and a height of 
about 12 feet. 

To insure the necessary headroom for street traffic no tree that 
forks at less than 10 feet above the ground should be used, and 
no branch whose base is less than 7 feet above the pavement should 
be retained. Contrary to a common belief, the branches of a tree 
remain fixed forever at one height above the ground; their bases 
are not carried upward by growth. (Frontispiece.) 

Trees to avoid. Silver Maples, Poplars and Willows are rapid 
growers but short lived, easily broken and given to producing sur- 
face roots and suckers. Locust is thin foliaged and subject to a 
boring insect. Nut trees invite injury by their fruit. 

Location. If conditions permit it, trees usually should be 
planted inside the sidewalk rather than close to the curb. There they 
are less subject to injury, their roots have more room, their crowns 
are less in contact with overhead wires, and they shade the houses 
better. Wherever space permits it is well to depart from straight 
lines. 

Intervals. Street trees usually are planted too closely together. 
The proper distance will be determined to some extent by the 
species, the width of the sidewalk and the front width of the build- 
ing lots. A safe rule is so to space the trees that their crowns 
will never interfere, but have considerable air and light between. 
Thirty feet is a minimum interval ; fifty feet or more is better. 

When to plant. Trees can be planted at any time when they are 
not in leaf. They are most apt to succeed if planted in spring, as 
soon as the frost is out of the ground. A cloudy, quiet day is bet- 
ter than a bright or windy one. (See p. 10.) 

How to plant. Dig the hole before the tree arrives and follow 
instructions given in figure 3. If the local soil is poor make the hole 
at least two feet larger and one foot deeper than is required. Re- 
move the poor soil and bring good, rich loam. Cut off all broken 
roots but save as many as possible of the small fibrous ones. Be 
careful that the roots do not dry out. Put enriched earth in the 
hole until the tree when standing upon it will be two inches lower, 
not more, than it stood in the nursery. Hold the tree upright, fill 
in the mixed soil and fertilizer and compact it firmly about the roots. 



8 



SHADE TREE GUIDE. 



Use plenty of water to settle the earth and be sure that every root 
is firmly embedded. Many newly planted trees die because their 
roots are left in air pockets. When all is done rake the surface 
to check evaporation. Successful tree planting depends upon care 
at every point a vigorous tree with plenty of good roots, an ample 
bed of good soil for root growth and careful planting are of prime 
importance. Then frequent watering, occasional cultivating, and 
fertilizer once a year. If these things are ignored a tree may live 
but will never thrive. 



WELL DEVELOPED HEAD, 
STRONG LEADER, BRANCH- 
ES SET AT WIDE, NOT 
CLOSE, ANGLES. 



DIG HOLE 18 IN. OR MORE 
DEEP; THEN FILL TO 
LOWER ROOT LEVEL WITH 
MIXTURE OF 3/4 GOOD SOIL 
AND'/4 ROTTED MANURE. 



BEFORE SETTING, TREE 
SHOULD BE PRUNED AT 
POINTS INDICATED BY 
" \CK LINES; NOTBYCUP- 
NG ENDS Of BRANCHES 



BASE. OF 
PERMANENT 
CROWN 
10 FT. ABOVE 
PAVEMENT. 



STAKE 2&IN.X 10 FT. 
DRIVCN 2 FT. IN GROUND 
AND SECURED WITH 
RUBBER COVERED WIRE, 
OR WITH CANVASS 



BASE OF TEMPORARY 
CROWN 7 FEET 
ABOVE PAVEMENT. 



OPENING IN SIDEWALK 
AT LEAST 6 SQ.FT.; 
KEEP TOP SOIL 
PULVERIZED 



PRESERVE FIBPOUS 
ROOTS: CUT OFF 
SMOOTHLY EVERY 
BROKEN ROOT. 



SET TREE SO 
IT STANDS 

IN. DEEPER 
THAN IT DID 
IN THE NUI2 

SECY 




PICH EAPTH PACKED 
FIRMLY ABOUT ROOTS 



Fig. 3. How to Plant a Street Tree. It is Important 
to Observe Every Point Indicated in the Diagram. 



STREET TREES. 9 

How to keep trees healthy. Any tree will resist insects and dis- 
ease, and will recover from injury much more readily if it is vig- 
orous and healthy than if it is weak. Observe the following rules : 
Never let a sidewalk be laid closely about a tree ; a surface of bare 
earth (footing) at least 2 by 3 feet, preferably 4 by 8 feet, should 
be kept (figs. 2, 3, 5) ; when a tree is fully established this may be 
grassed over, tho it is advisable to keep it open. Once a year work 
a little fertilizer into this open space and water it at intervals as di- 
rected at page 13. 




Fig. 4. A Young Street Tree. Fail- 
ing Thru Lack of Care Of Poor 
Form, with Branches too Low, It 
is Crowded in a Brick Pavement, 
Has no Stake and Only a Short, 
Frail Guard. 



Fig. 5. A Young Street Tree of 
Good Form, Properly Planted and 

Well Cared For Guard, Stake, 

Footing as They Should Be. 



If a young tree is exposed to winds or other strain, keep it firm 
and upright by means of a stout stake to which the stem is secured 
in such fashion that it will not be rubbed (fig. 5). Unless the tree 
is so placed that it cannot be gnawed by horses maintain a stout 



IO 



SHADE TREE GUIDE. 



guard about it (figs. 5, 7). Apart from the pruning required when 
a tree is planted most trees should be allowed to develop naturally. 
Priming as frequently practiced in butchery. (See p. 19 and fig. 12.) 
Allow no tree to support a guy wire except under necessity. In that 
case, and only if the tree is strong and healthy, let an eye bolt be 
driven into the heart, or all the way thru, and the guy wire at- 
tached to that ; no form of band should be tolerated except tempo- 
rarily in an emergency. 






Fig. 6. Trees Should Not Be Used to Anchor Guy Wires Except in an 

Emergency. 

A Never Attach a Guy in This Way. 

B A Temporary Guy Should Have Wood Blocks Under the Wire. 
C If a Tree is Sound, a Lag Screw Driven Into the Heart Will Hold 
a Guy Wire and Do Least Harm. 



Lawn Trees 



Planting. Any tree with ample space about it requires only 
to be secured against injury and to be supplied with food and water. 
Deciduous trees should be planted exactly as recommended for 
street trees except that stakes and guards are rarely required. Ever- 
green trees, and a few deciduous species with succulent roots, as 
Red Gum, must invariably be moved from the nursery with the 
roots embedded in a ball of earth. When the hole has been pre- 
pared and good earth supplied, loosen the bagging that encloses the 
ball and set the tree with the earth still about its roots. 

As a rule lawn trees, like street trees, do best when planted in 
early spring, tho evergreens allow greater latitude and often thrive 
when moved in August. When that is done it is important to guard 
them against strong winds in winter. 

Lawn trees ordinarily require less care than street trees, but a 
circle at least 3 feet in diameter should be kept without sod about 
the base of a newly planted tree of whatever kind, and the soil with- 
in it worked frequently, until the tree is firmly established. Grass 



LAWN TREES. 



ii 



may then be allowed to grow, altho it is advisable to maintain the 
opening continually as a guard against injuring the base of the tree 
by the lawn mower. 

"Wells" and mounds. If the level of the ground about an old 
tree is changed a "well" must be built in a fill to keep the soil away 
from the trunk and to avoid smothering the roots, or a mound left 
on a cut to prevent exposure. 



B 






Fig. 7. Four Types of Tree Guards. 
A Standard in Washington, D. C. Made of Wood and Very Strong. It 

Also Serves as a Support, but is Unsightly and Not Cleanly. Cost 

About $1.50. 
B Made of Ornamental Fence Wire. Too Frail to be of Much Value 

as a Guard and of None as a Support. Cost About $1.00. 
C Made of Heavy Wrought Iron. Is Attractive, Strong and Durable. 

Cost With Grill About $10. 
D Made of 1-2 inch Galvanized Iron Screen, with Rubber Hose Buffer at 

Top. Harbors Insects and Must be Supplemented by a Supporting 

Stake, but Very Popular. Cost About 80 Cents. 



Seashore Trees 



Whether along the streets or upon lawns, trees near the ocean 
have to contend with poverty of soil, deficient soil moisture and 
strong winds, those of winter in particular. It is useless to try to 
maintain trees where they can be reached by ocean spray say with- 
in 200 feet of high water. Beyond that point it is simply a question 
of choosing hardy species and strengthening sterile soil. 






12 SHADE TREE GUIDE. 



Fertiliser. It is not necessary to transport inland soil, the poor- 
est sand may be treated thus : 

Add to the native soil : 

Oyster shell lime 9 pounds 

Wood ashes 2% 

Composted (not fresh) manure 50 

Or as a substitute for the manure, not 
in addition, 
A mixed fertilizer composed of: 

2 parts tankage 

ground fish I .. 2l/ 2 pounds 

3 acid phosphate 

3 " muriate potash J 

The quantities named are enough for 100 square feet of ground. 
As root spread is assumed to be equal to crown spread, a tree with 
a crown 6 feet in diameter will have roots covering about 30 square 
feet and will require three-tenths of the above. Do not use more or 
the trees will be injured. Apply the fertilizer every spring; the 
lime and wood ashes every three or four years. As a sandy soil is 
always porous frequent and abundant watering is necessary. 

Support. Until it is firmly established every tree exposed to 
strong winds must be firmly supported by a stout stake or by three 
or four wires secured to pegs firmly driven into the ground. This 
is even more important in winter than in summer. 

What to plant. For street planting the choice of species should 
be limited to sycamore, ailanthus, pin oak, scarlet oak, red oak, hack- 
berry, honey locust, red maple, and. in most situations preference 
given in the order named, altho it is not advisable that too many of 
the same kind be used. Upon lawns oaks and pines, with various 
hardy shrubs, are to be preferred to the firs, spruces and cypresses, 
and the many deciduous trees, that are available inland. 



Nourishment 

More trees suffer from starvation than from anything else. On 
lawns as on sidewalks a tree's natural food (fallen leaves, etc.), is 
taken away, water is denied and both rain and air are excluded by 
close pavements, or by sod. The consequent weakened condition 
induces disease and insect attack. Don't plant a tree unless it can 
have at least 6 square feet of open soil at its base. For several years 
after a tree is planted this is imperative, afterwards sod, not pav- 
ing, may be tolerated. Frequent working of the surface soil, as in 
any garden, will tend to keep a tree in good condition. 



NOURISHMENT. 13 

Water. Street trees require more water than lawn trees because 
their roots are apt to be restricted and because sun-heated pave- 
ments and buildings increase transpiration. A good rule is to see 
that the ground about a tree is soaked once a week. If rain fails 
use the hose or a pail. Sprinkling, tho done frequently, is only a 
little better than nothing. Too frequent soaking will exclude the 
air and cause the roots to rot. When the ground has dried after 
a wetting, rake the surface to check evaporation. If the ground 
does not dry within an hour too much water has been applied. 

Food. In the forest, and in neglected places, nature provides 
trees with food. Along the streets and on well-kept lawns it must 
be furnished. If a tree shows thin foliage, slender branches or a 
dead top starvation may be suspected. The best fertilizer is com- 
posted (not fresh) manure. In the spring spread it 2 inches deep 
over as much of the root extension as can be reached and fork it 
into the soil; or, tho not so good, put it on December first and let 
it lie over winter, when what remains can be raked off. On a paved 
street the fertilizer must be placed in the opening at the tree base, 
but whenever possible it should be spread away from the trunk and 
beneath the foliage, where most of the feeding roots are found. If 
manure is objectionable, apply each spring iVz pounds per 100 
square feet of a commercial fertilizer composed as follows : 

For light soils. For heavy soils. 

Nitrate soda i part 2 parts 

Acid phosphate i " 3 " 

Muriate potash 1 i " i " 

Ground bone i " 2 " 

Distribute the fertilizer evenly and mix it with the soil ; be care- 
ful not to use an excess else the tree roots may be burned. 

If it is desired simply to sustain an old tree without inducing 
growth, use a small quantity of manure, or from i to i!/2 pounds per 
100 square feet of a mixture containing i part nitrate soda, i part 
bone meal, 5 parts acid phosphate. 

Pruning 

Trees need to be pruned only (i) when they are transplanted; 
(2) when they interfere with other trees or structures; (3) when 
they are weakened by decay or by overgrowth. Much of the prun- 
ing done by so-called experts is useless or even harmful. Most trees 
should be allowed to develop according to their natural habit. When 
pruning is permissible the following rules apply. 

When transplanted, a tree must have its crown cut back to bal- 
ance the inevitable loss of roots. See figure 3, and observe that 
useless interior branches are removed entirely. 

Form. If a tree grows one sided, if its branches interfere with 
a building, or with another tree, curtail or cut out entirely the aggres- 



ashes may be substituted at the rate of 10 pounds to 1 pound 
of muriate potash. 



SHADE TREE GUIDE. 



sive member. With few exceptions trimming the ends of branches 
is wrong and cutting off the whole top is butchery. 

Branches which hang too low should not be trimmed, but cut 
back to the trunk or main branch. If branches grow so that they 
interfere with electric wires, either have the wires lowered, or re- 
move entirely all but the three or four most vigorous shoots and 
stimulate the tree to carry a crown above the wires. (See p. 19.) 
For treatment of heavy limbs see Injuries, page 15. 

Vigor. If a tree is so weakened that dry branches appear, cut 
out all the dead wood, and such of the living members as Is neces- 
sary to make the tree shapely. If lack of vigor is shown by droop- 
ing foliage and the crown is very dense (as is common in Norway 
maples and sugar maples), relief will be given by removing a quarter 
or a third of the foliage. This should be done, not by cutting off the 
extremities, but by taking out interior branches entire (figs. 8, 9). 
When done skilfully the appearance of a tree as well as its strength 
is improved. After pruning for vigor a tree should always be well 
fertilized and watered. 



\. K 






Fig. 8. Diagram, from a Photo- 
graph, of a Norway Maple Show- 
ing the very Dense Crown 
Common with this Species. The 
Foliage Produced Makes a Heavy 
Draft upon the Soil Fertility and 
Water and Frequently Leads to 
Wilting. 



Fig. 9. The Same Norway Maple 
as that Shown in Fig. 8 with 
Superfluous Branches Removed 
by an Interior Pruning. This 
Preserves the Natural Form of 
the Crown and a Frame that will 
Produce as much Foliage as is 
Desirable. 



Covering cuts. Unless it is properly treated every break in the 
bark of a tree affords entrance to disease germs. In practice clean 
cuts less than an inch in diameter are ignored; every larger wound 
should be coated with an antiseptic. The most practical is creosote 
followed by coal tar. Tar alone is often used, but does not pene- 
trate deep enough to give best results. Creosote is a dark oil and 
can be applied with a brush. Tar should be made liquid by heat and 
applied in the same way. It is advisable to avoid covering the cam- 
bium. 



INJURIES. 



Time to prune. Pruning may be done when it is most convenient 
unless "bleeding" (p. 21) is induced. That is most apt to occur 
in early spring or early fall. Late winter is usually best because 
there is then little sap movement and the absence of foliage makes 
the work easier. (See p. 8.) 

Injuries 

Broken limbs. Every broken limb should be cleared away 
promptly by a cut, or succession of cuts, that leave a wound which 
will heal quickly. Small limbs can be taken off by a single cut, 
larger ones require three, as indicated at B, figure n. It is im- 
portant to use a sharp saw, make the final cut close to the larger 
member and be careful that the bark at the bottom is not torn. A 
wound shaped as indicated at RIGHT, figure 10, will heal most 
quickly ; one shaped as indicated at WRONG will heal more slowly at 
the top because the arch is flatter, and very slowly at the bottom be- 
cause the bark is torn away. A stub as at C, figure u, should never 
be left. The face of the wound should be treated as directed on page 
14. Cement will do harm rather than good. 



I RIGHT 

wr 




WCONG 

'*! 



Fig. 10. Cut Marked RIGHT is Healing Properly and 
Quickly. Cut Marked WRONG is Healing Slowly, and 
Not at All at the Bottom, Where the Bark is Torn. 
Every Wound on a Tree that Can be so Treated, 
Whether a Mere Bark Bruise or the Stub of a Severed 
Limb, Should be Trimmed to a Long, Regular Oval. 



16 SHADE TREE GUIDE. 

Frost cracks, sun cracks, and winter kill. Extremely cold 
weather, especially when it follows a late growing season, some- 
times freezes the water in the outer cells of a tree stem and causes 
a long crack. Thin-barked species, like sycamore and horse chest- 
nut, are most susceptible and any tree on a street, exposed as it 
must be, is apt to suffer. Sun cracks have the same appearance but 
are caused by excessive heat, often reflected from a white pave- 
ment or wall. In large trees such cracks usually close again with 
warmer weather and no serious harm is done, but the wood does 
not unite and a scar is left. On small trees the crack is apt to per- 
sist until new growth covers it. There is no practical preventive, 
and no remedy other than helping nature by every care to heal the 
wound. This can be hastened by treating the crack with antiseptic, 
and keeping it from reopening by strong staples, driven in warm 
weather when the gap is narrowest. "Winter kill" occurs when the 
vital parts of a tree trunk are frozen and ruptured in a horizontal 
plane by the formation of ice about its base. There is no remedy, 
but the trouble can usually be avoided by having the ground slope 
away from the foot of a tree on all sides so that no water can col- 
lect there. "Winter kill" is common on the terminal shoots of many 
trees and shrubs and rarely does permanent harm. 

Abrasions. Surface wounds, made by horses, lawn mowers, 
blows, etc., are the starting places of most of the decay that de- 
stroys shade trees. It is little realized that many serious tree wounds 
originate between the nursery and the planting site. If the trunk 
of a young tree is thrown on the side-board of a wagon the tender 
bark and cambium are apt to be crushed, and tho the injury may 
not show at the time the growth of the surrounding parts reveals 
it. Every care should be taken to avoid these injuries. When one 
occurs let the injured part be cut out carefully with a sharp knife 
or chisel until sound wood is exposed and the edges left smooth. 
Then sterilize and tar the wood not the cambium or bark, and leave 
the rest to nature. Cement should not be used. (See F and H, fig. 
n.) 

Cavities. Cavities in trees are invariably the result of decay. 
They are treated with one or all of three objects in view: (i) to 
stop the decay and induce healing; (2) to hide an unsightly part; 
(3) to support a weakened body. The belief that every cavity 
should be filled is wrong, because, even with the best workmanship, 
a filling merely retards decay, it does not stop it. The best rule is 
to clean a cavity thoroly cutting out all decayed tissue with a 
gouge and mallet until sound heart wood is exposed. If the cavity 
will not hold rain water, or the wound is not unsightly, trim the 
edges neatly, treat the wood surface and stop. 



INJURIES. 



PREVENT A SPLIT OR 
MEND A SPLIT BY CHAIN 
a BOLTS. NOT BY A BAND. 

sec 



A DECAYED BRANCH 
AS C. CUT OFF & 

THE CAVITY CLEANED 
FILLED. 




A LONG STUB LEFT. 
DECAY HAS SET IN 
IFNOT TREATED 
AS AT M WILL 
BESTROT THC MAIN 
LIPIB. 



A WOUND FiLLEO 
UNNECESSARILY, 
TREATMENT AS 
E OR K WOULD 
BE BETTER. 



NEVER MEND A 
SPLIT WITH A 
BAND, THE TREE 
WILL SOON DC 
CHOKED, SEEA&D 




A SOLID BAR WITH 
NUTS WILL HOLD A 
WEAKENED CROTCH 
THOUCH, IN A BIG TREE, 
NOT SO WELL AS A 
CHAIN. -SEE A . 



WHEN A LIMB IS 
REMOVED AND THERE 
IS SLIGHT DECAY. CLEAN 
OUT THE WOUND & TAR 
BUT DO NOT FILL IT. 



TREAT A BRUISE AS 
H BY CUTTING OUT 
INJURED TISSUE. 
LEAVING SURFACE ft 
EDGES SMOOTH. TAR 
BUT DO NOT TILL. 



A. LARGE CAVITY 
PROPERLY FILLED 
WITH CONCRETE. 



Fig. 11. The Right and Wrong of Tree Doctoring. 

If the cavity cannot be drained, if it is unsightly, or if the tree 
needs support, a concrete filling may be placed. Before doing this 
any but a pocket cavity should be shaped so that moisture will dram 
from it, and set with nails or wires to hold the concrete in place. 

In many cases it is advisable simply to clean the cavity, and, 



i8 SHADE TREE GUIDE. 

without attempting to fill it, cover the opening with cement, sheet- 
metal, or wood blocks (creosoted), to guide the growing callus. 
For small cavities a mixture of half cement and half sand is best; 
for larger ones one part cement, one part sand and two parts 
gravel, broken stone or cinder will ans\ver. The surface of a fill- 
ing may be smoothed with a coat of clear cement. The sand, stone 
or cinder should always be free from dirt of any kind, the cement 
thoroly mixed and as soft as it can be handled. 

Gas poison. If illuminating gas escapes from a faulty pipe into 
the soil in which a tree grows the roots may be poisoned, cease to 
function and the tree be weakened or killed. The extent of the 
damage, and the rapidity of action, depend upon the quantity of gas, 
the porosity and moisture of the soil, and the character of the pave- 
ment or other ground cover. A little gas may find its way to the 
air and do no great harm ; a large quantity can kill in a day every 
tree whose root system it penetrates. If a tree is killed while it is 
leafless, it may give no sign until the following spring when its foli- 
age fails to come out, or, coming out, is weak and soon falls. The 
only sure test for gas is the odor. If a leak is suspected make a 
hole with a crowbar or auger about two feet from the tree and two 
or three feet deep and apply one's nostrils to the opening. If gas 
is indicated the leak must be found and stopped at once. Some- 
times a tree subjected to gas can be saved by trenching about it and 
watering the soil freely, but most cases are hopeless unless only a 
little gas has escaped. 

Fire must not touch a valued tree. Even the slight heat given off 
by a burning leaf pile may cause serious injury. 

Salt, lime. Many trees are killed by having brine from ice- 
cream tubs, or from salt used to melt pavement ice, penetrate to 
their roots, and some are lost by an excess of lime water washed 
from nearby mortar beds. Preventive measures only are effective. 

Electricity. Ordinary electric currents never injure the vitality 
of a tree, and wires carrying a high potential current which might 
do damage, especially in wet weather, are bound to be properly in- 
sulated to save loss of power. The injury that trees suffer from 
electric wires is invariably a cutting or local burning caused by 
friction between a loose wire and a branch, or, more often, the 
mutilations performed by careless or ignorant linemen. The rules 
of the electric companies forbid their employees to use any tree 
without the consent of the owner and provide for expert super- 
vision of any tree trimming that is authorized. Linemen fre- 
quently ignore these rules, but no tree need suffer if its owner will 
take the trouble to report the case to headquarters before the dam- 
age is done. In many cases the company will completely trim and 
fix up a tree for the privilege of carrying their wires thru it. In 
this State an owner should always be represented by a Shade Tree 
Commission. 



STREET TREES. 




Fig. 12. A Row of Old Trees Butchered to Make Room for High 
Wires. Compare With Fig. 13. 




Fig. 13. The Same Trees as in Fig. 12, With Crowns Saved and 
Wires Carried Thru Them in Cables on Low Poles. 

The construction of electric lines is a necessity of our civilization ; 
the cost of carrying the wires underground is prohibitive except in 



20 SHADE TREE GUIDE. 

cities where the service is concentrated; they must therefore be 
carried on poles along the streets and must be accommodated to ex- 
isting structures and trees. In making these accommodations five 
rules will govern: 

1. Set the poles as far out of the tree line as possible, to avoid 
interference. 

2. Use low rather than high poles. Where the trees are small, 
and in line with the poles, it is necessary to carry the wires above 
them, but as they grow, lower the poles so that the wires may be 
carried, on offsets, brackets and insulators, away from or thru the 
firm bodies of the trees. A wire fastened so that it does not rub 
can do no 'harm ; a bolt carefully driven into the heart of a branch 
to support an insulator or a cross arm is always justified; but any 
vigorous tree will soon outgrow the practical height of electric poles. 

3. Let cross arms and insulators be fastened to strong trees, 
rather than set poles, where the wires can be properly carried. 

4. Provide guard strips on the trees and abrasion moulding on the 
wires wherever there is movement and a chance that the tree and 
the wire will rub. The removal of small interior branches to make 
a clear way for a wire is more apt to be a benefit than an injury to 
a tree. 

5. Have all cuts larger than I inch diameter made smooth and 
carefully treated (see p. 14), to prevent the entrance of disease 
germs. Prohibit absolutely the use of climbing spurs in any tree. 

Diseases 

The diseases of trees are chiefly due to abnormal soil or climatic 
conditions, to injuries, or to parasitic fungi. The latter sometimes 
are very destructive, as in the case of the chestnut blight; more 
commonly, as the sycamore anthracnose, they affect the foliage 
more or less seriously, but do little permanent harm. Fortunately, 
most diseases attack only one tree species, or one genus, a law 
that makes diagnosis and control less difficult than they would be 
otherwise. If a tree begins to fail without apparent cause, it should 
be questioned (i) whether it lacks water; (2) whether it stands 
in sterile soil and lacks fertilizer. If either deficiency is discovered 
the remedy is obvious (see p. 13). If it is not, a specialist may 
be helpful; often he can do nothing. If the fleshy fruiting bodies 
of a fungus appear, the tree, or its affected member, is seriously 
diseased, and surgery, or the tree's removal, is indicated. It fre- 
quently is better to ignore the signs of internal decay than to start 
a cutting which may have no practical limits. Many trees live for 
years with their heartwood completely gone. (See Cavities, p. 16). 
It is important to distinguish the fungus fruits which appear only 
on dead wood, from those which are parasitic. A special publica- 
tion, "Common Diseases of Shade Trees," can be obtained upon re- 
quest of the State Agricultural Experiment Station, New Bruns- 
wick. 



DISEASES. 21 

Wilting. The leaves of shade trees frequently wilt out of season. 
Sycamores are apt to lose their first leaves in the spring from a 
prevalent disease, but soon get a second set and usually suffer lit- 
tle permanently. No specific treatment is advised. Other species, 
especially maples, are beset with lice or scale insects which by suck- 
ing their juices cause the leaves to die. If the attack is slight let 
nature take care of it ; if it is serious spray as directed on page 22. 
But most trouble of this kind is found in Norway and sugar maples ; 
the cause is obscure, yet there is reason to believe that too little food, 
sometimes too little water, is available to nourish the heavy leafage 
that these trees produce. Feeding and watering (p. 13) will usually 
prevent this trouble ; if it develops, let the foliage of the affected tree 
be curtailed by an interior pruning (p. 14), then fertilize. (Figs. 

8,9.) 

Bleeding. This frequently occurs when branches are cut while 
the sap is moving freely. Under such conditions stop all pruning as 
loss of sap lowers the vitality of a tree. 

Another sort of bleeding, sometimes called "slime-flux," and hav- 
ing an offensive odor, usually begins in a wound, or behind a filling, 
and is often hard to manage. Like a sore in the flesh the worst 
possible course is to stop it from the outside ; it must be cleansed, 
sterilized and made to heal from the inside. Let all affected tissue 
bark and wood, be cut out with a sharp chisel, the wound pointed 
at top and bottom (fig. 10) and all edges left smooth : sterilize the 
exposed surfaces with weak formalin and cover with tar; never 
use cement. If the trouble is due to a split crotch, clean the crack 
as well as possible, bolt the parts together, as at D, figure n, and 
treat as above. 

Insects . 

Not all insects are harmful to trees: some, tho harmful, are so 
controlled by natural enemies that they rarely are found in num- 
bers great enough to do serious damage; others attack only trees 
that have been weakened by neglect or injury. 

As with diseases, harmful insects usually confine their attacks 
to trees of one species, or one genus. Thus the elm beetle attacks 
elms only, the hickory borer only hickories. It is entirely safe to 
say that a few insects of any kind on a vigorous tree will do little 
harm ; a few insects on a weak tree should be looked after, and many 
insects on any tree demand prompt attention. But to be always on 
the safe side every suspected case should be referred to some au- 
thority an entomologist or a forester. Ants are rarely harmful ; 
their presence about a tree usually means that honey dew, decayed 
wood or fungus growths are available for their food. 

Injurious insects are grouped in three classes: biters, suckers, 
and borers. 



SHADE TREE GUIDE. 



Biters. These commonly attack the foliage and may work as 
adults (beetles) or as larvae (caterpillars or worms). Control is 
determined by a knowledge of the life history of each species, but a 
general remedy is to poison their food. The best means is to 
spray thoroly with arsenate of lead according to directions given on 
the commercial packages. Banding a tree trunk with cotton or 
some sticky stuff is useful only when the insects are crawling up. 
Bag worms, tent caterpillars, etc., which form conspicuous shelters 
or colonies in tree crowns, and forms like tussock moths which set 
egg masses on nearby structures, as well as on the trees, can often 
be destroyed by hand or by fire even more successfully than by 
spraying. 

Suckers. These appear as minute, crawling insects, frequently 
protected by woolly, waxy or scaly coverings. They locate on the 
younger branches, or on the leaves, often in enormous numbers, and 
live by sucking the sap. Some forms can be washed away with a 
strong jet of water from a hose, but in most severe cases thoro and 
repeated spraying with a caustic, or with a penetrating oil, is neces- 
sary. Fish-oil soap suds is good for the tenderer forms, especially 
when reinforced with tobacco extract; lime-sulfur or soluble oil is 
best for those with scaly armor. 

Borers. Boring insects work, as beetles or worms, in the twigs 
or buds, in heartwood, or, most frequently, in the cambium layer 
between sapwood and bark. Their presence is indicated by broken 
branches and by small holes in the bark beneath which wood dust 
is often found. In our territory a few species attack healthy trees, but 
most seek out those whose vitality has been lowered. Control is dif- 
ficult because the pest is mostly out of sight, and, tho help can some- 
times be given, it usually is necessary to depend chiefly upon keep- 
ing the trees in good health. Against the locust borer anything else 
is useless. Any hickory tree that is seriously infested with the hick- 
ory borer is doomed and should be cut down and burned without de- 
lay for the sake of nearby trees, and the latter should be stimulated 
by feeding to ward off attack. Leopard-moth larvae are especially 
fond of young, newly-planted street trees which are struggling to 
establish themselves. A measure of control is possible by cutting 
out the boring worms, by crushing them with a wire run into the 
burrows, by injecting carbon bisulfid, and especially by encouraging 
insect eating birds. More specific advice is given in a publication 
of the State Agricultural Experiment Station, New Brunswick, "In- 
sect Enemies of Ornamental Trees and Shrubs/' by Harry B. Weiss, 
which will be sent upon request. 



6 ! D JU 



